It is common to use conduits to carry various fluids from one location to another. These conduits usually consist of a plurality of sections or segments joined together to form a continuous fluid communication pathway, commonly referred to as a pipeline. Pipelines are essential to most industries. Pipelines are used to transport liquids, gases, and other chemically stable fluids, such as water, sewer, and refined petroleum.
Flanges are an integral part of a pipeline, as they provide the connections necessary to link the sections of pipe that form a pipeline. Flanges also serve the purpose of incorporating valves and other fittings into the pipeline. A typical flange is a disc, collar, or ring that forms a rim at the end of a section of pipe. The disc, collar, or ring is typically welded to the end of the section of pipe to form the flange.
When two sections of pipe are equipped with flanges and joined together, a flange joint is formed. The flange joint is typically held together with threaded bolts and accompanying nuts, where the bolts extend through holes in the rim of the two flanges. Similar flange joints can exist between a section of pipe and a valve or other fittings.
Each flange has a flange face for mating with another flange face when a flange joint is formed. Flange gaskets are generally used to create a mechanical seal between two mating flange faces. When two mating flange faces are compressed together, a flange gasket inserted between the two mating flange faces typically fills the microscopic spaces and irregularities of the mating flange faces to prevent leakage from or into the flange joint.
One of the more desirable properties of a flange gasket, particularly in industrial applications, is to protect a flange joint from galvanic corrosion. In some applications, the fluid inside a pipe is highly caustic, leading to the deterioration of some types of flange gaskets and flanges, which can cause leaks and flange failures. To prevent such leaks and flange failures, the present invention provides a deformable seal on the inner diameter of the gasket, thereby protecting the integrity of the gasket from the fluid in the pipe and preventing the corrosive material from attacking the flange faces.
Providing a deformable seal on the inner diameter of the gasket also serves to protect gaskets that utilize a metal core. When these type gaskets are installed on pipelines carrying conductive fluid, the exposed metal core can act as a bridge between the two flanges, resulting in a “shorted” connection and loss of electrical isolation. The deformable seal on the inner diameter of the gasket prevents contact between the fluid in the pipe and the metal core of the gasket.
The challenge with developing a gasket having a deformable seal on the inner diameter of the gasket is to create a robust retention mechanism that keeps the deformable seal secure to the gasket during handling and shipment of the gasket, and also prevents the deformable seal from being drawn into the pipe in the event of drastic pressure changes.
As discussed in more detail below, the present invention is a flange gasket having all three of the desirable properties mentioned above.